Explanation of the Earth's gravitational field, emphasizing how USGS scientists measure gravity and portray these measurements on maps. Explains terminology of gravity anomaly maps and their relationship to the rock types and other geologic features.

Macroinvertebrate data collected by USGS or USFS from 73 sites from 2000 to 2007 and algal data collected from up to 26 sites between 2000 and 2001 in the Eagle River watershed, with emphasis on methods of sample collection and data processing.

Water from this reservoir will be used more extensively by the city, so we are developing methods of assessing the water quality in real time by measuring characteristics of stream flow that correlate with important water quality data.

Instructions on how to build a protective outdoor seismic vault used as stations for broadband seismic sensors that respond to seismic energy, temperature, and atmospheric pressure for the United States National Seismic Network in PDF format.

Field manual (also available in PDF and paper formats) with instructions on techniques to collect and process water samples and to perform measurements of temperature, oxygen content, conductance, pH, turbidity, and fecal contaminants.